New Nor‐sesquiterpenoids with 10‐ epi ‐eudesmane skeleton from agarwood ( Aquilaria agallocha Roxb. )

Six new nor‐sesquiterpenoids with the 10‐ epi ‐eudesmane skeleton were isolated from agarwood oil ( Aquilaria agallocha Roxb.): ( 2R ,4a S )‐2‐(4a‐methyl‐1,2,3,4,4a,5,6,7‐octahydro‐2‐naphthyl)‐propan‐2‐ol (5a) , ( S )‐4a‐methyl‐2‐(1‐methylethyl)‐3,4,4a,5,6,7‐hexahydronaphthalene (6) , ( S )‐4a‐methyl‐2‐(1‐methylethylidene)‐1,2,3,4,4a,5,6,7‐octa‐hydronaphthalene (7) , (2 R ,4a S )‐4a‐methyl‐2‐(1‐methylethenyl)‐1,2,3,4,4a,5,6,7‐octahydronaphthalene (8) , (1 R ,6 S , 9 R )‐6,10,10‐trimethyl‐11‐oxatricyclo[7.2.1.0 1.6 ]dodecane (9) and (1 R ,2 R ,6 S ,9 R )‐6,10,10‐trimethyl‐11‐oxatricyclo [7.2.1.0 1.6 ]dodecan‐2‐ol (10) .